Gas-fired oven or kiln



Apr. 24, 1923. v1,452,887

J. H. MARLOW GAS FIRED OVEN 0R KILN Filed May 1'7 1921 2 Sheets-Sheet l Apr. 24, 1923.

J. H. MARLow GAS FIRD OVEN 0R KILN Filed May 17, 1921 2 Sheets-Sheet 2 Flay.

Patented apr. 24, i923 i y l i loFFlcu. l

JOHN HENRY MAB/LOW, OF STOKE-UPON-TRENT, ENGLAND.

oas-risen oven on K'ILN. y

Appucauon mea May 17, 1921. serial No.l 470,265.

To all whom z'z may concern.' through the side walls of the oven as will' Be it known that l, JOHN HENRY MAR- be understood. rl`he air conveyed by the 10W, subject of the King of Great Britain pipes Z enters chambers e `and after passing and Ireland, and resident of Stoke-uponthrough an outlet 7" in the wall thereof it rFrent, in the county of Stafford, England, meets the incoming gas in the chamber l 55 manager, has invented certain new and usewhere combustion takes place and the iame ful Improvements in or Applicable to Gasis produced. rThe flame from the combus- Fired Ovens or Kilns, (for which l have tion chamber l passes through openings g made application for patent in Grrcat in the wall thereof and into a second kcom- 10 Britain, numbered 22,641, dated the 30th of bustion chamber 2 being then conducted to- 60 July, 1920), of which the following Lis la wards the inlet or front end ofthe oven specification. by way of a passage it which is of irregular My invention relates to improvements in depth, or stepped as shown to diminish toor applicable to gas-fired ovens or kilns for ward the front to interrupt or control the l5 use in the manufacture of tiles, pottery and passage of the gas so as to equalize the sup- 65 other ware and for other purposes, the obplythereof to the orifices, pipes or burners ject being improved means for conveying y? thereby preventing the rush of gas to the and controllingl the gas and air so as to far endof the passage h or to the farthest greatly increase the intensity of the heat pipe or burner p. The said' orifices, pipes,

in the oven to effect the ware therein and to or burners p may be of varying diameters, 70 economize in the use of fuel. the largest opening or bore of the pipes be- My invention will be fully described with ing nearest to the combustion chamber` 2, reference` to the accompanying drawings in as shown in the drawings. Sometimes it which, may be an advantage to employ pipes or Fig. 1 is-a sectional plan of a portion burners of irregular or varying heights. 75 of a tunnel oven constructed in accordance The air issuing through pipes d is with my invention, dampered or cut off when the temperature Fig. 2 is a sectional elevation through line of the heat in the oven rises to a .predeter- Y-Y of same, mined degree and an independent supply Fig. 3 is a transverse section through line of hotair is introduced through the ends j2` 80 Z-Z of Fig. 1, and ofthe pipes jinto the chamber la, through Fig. 4 is a portion of Fig. 3 slightly modian opening m and into the chamber 2 fied to be herein referred to. where it meets the incoming. gas passing ln these figures U is a tunnel oven, V the from the chamber 1, `through opening g,

interior thereof and W the carrier or travcombustion then taking place in the 'second 85 elling vehicle for conveying the wa-re'to be combustion chamber 2. The said vpipes j treated, these parts being of the usual well extend longitudinally of the oven 'and are known construction. built on or supported by baffles o to expose ln accordance withmy said invention the a great portion of the surfaces of the pipe 40 gas is conveyedfrom the usual gas producer j to the flame projected thro-ughthe pipes or 90 y into channels a arranged at each side of the orifices p, the air passing therethrough beoven, the gas passing through an opening Z) ing superheated or raised to a very p great which is controlled by a damper c and then intensity prior to its entry into. the chamber into the combustion chambers 1 which is lo- 7c, from which chamber the air passes'into cated beyond the main vertical walls R of chamber 2where combustion taires place, the 95 the oven, as shown. The necessary rsupply flame produces therein travelling through of air to be mixed with the gas passes passage h tothe burners pand into the inthrough' a series of pipes el arranged longiterior of the oven to treat the ware passing. tudinally from the outlet end X of the oven, therethrough on the carrier W. The walls but in some cases such pipes (Z may extend of the chambers le. extend upward to join 100 the inner arch, or they may be covered by a plate or top wall.

As will be seen from the sectional plan at Fig, 1 two gas supply channels a, one at each side of the oven, are employed to supply gas to either of the two combustion chambers l and2fandto the pipes or burners ai* ranged at each side of the oven. Combustion only takes place in combustion chamber l whilst air is being.admitted'through the pipes d, the combustion in chamber 2 taking place when the superheated airr from the pipes j passes from chamber lc. and meets the gas immediately it' has passedv from chamber l and into the combustion chamber 2. The said pipes j extended longitudinally. in adirection away from the inlet end Si offth'efoven but if desired the pipes may pass through the side walls of the oven and then extend longitudinally in close proximity to the. burners.

y The air pipes CZ are shown in dotted lines at` Fig, 3 for convenience rto locate their height onlyy but the outlet ends of such air` pipes are some distance in front of the combustion chambers 2 as will be clearly seen from Figsyl and 2.

AtF ig. 4 is illustrated a section of a small portionofthe interior of the oven slightly modified. The open spaces between the bafies o (Fig. 2) are covered with slabs n. of refractory material to enclose the air pipes j and burners p .anl thereby muiiie the flame from the orifices, pipes or burners p preventing the products of combustion or the flame coming into direct contact with the ware being passed through the oven.

As before'stated two gas supply channels are arrangedat each side of the oven but both. channels may communicate with one gas conduit leading from one gas producer, or if desired two separate gas producers may be employed as will be understood.

The cold airA inlet pipes d supply cold air to the gasas initially supplied to the burner, and this supply of air may be cut out or reduced, when desired, and when the furnace or kiln has been intially heated, a part of thel heatcaused by a mixture of gas and cold air, passes along to a-combustion chamber designated as the second combustion chamber. The cold air serves to form a gas and air mixture which is not as economical as a mixture of hot air with the same characterv of fuel gas. The air being heated is rarefied to a greater degree than the cold air, and the combustion is more perfect and automatic. In starting the kiln. the use of dampers` is essential, whereas with heated airjthey are not required.

What l claim as my invention and desre to .secure by Letters Patentis l. Atunnel oven or kiln provided on opposite sides with combustion chambers and air supply pipes, passages communicating with the combustion chambers, said passages ldecreasing in area towards the front of the oven or kiln, and a series of orifices which communicate with said passages.

2. A tunnel oven or kiln having chambers and means for the admission of air and fuel gas thereto, other combustion chambers into which the mixed air and gas is'passed from the first combustion chambers, means communicating with the.. second combustion chambers for supplying heated air thereto, and a forwardly diminishing passage provided at intervals with flame exit openings.

3. i kiln for the purpose set forth, consisting of a structure having` a tunnel with longitudinal side ledges, combustion cha-mbers and passages therefrom located below the plane of the ledges, vents through the ledges which communicate` with the passages, pipes maintained within the tunnel for supplying heated air to combustion chambers, and supports for the pipes that extend from the ledges of the tunnel upward to provide baiiies.

4l. A tunnel kiln which structurally provides on each side of the tunnel iues which are connected Awith a fuelgas supply, chainibers to which air is supplied, dampersfcontrolling a supply of. gas and air to said chambers, other combustion chambers in communication with the aforesaid mentioned chambers, air supply pipes maintained with' in the tunnel of the kiln to supply heated air to combustion chambers, stepped passages which communicate withthe combustion chambers, and spaced openings through the upper walls of said' passages.

5. Means for mixing air and gas for fuel inkilns, lcomprising channels and chambers into which air and gas are admitted, dampers for limiting the supply, of to the chambers, combustion chambers in communication with the intial chambers into which cold air is admitted, pipes maintained within the tunnel of` the kiln for supplying heated' air to chambers in the rear of the last mentioned chambers, passages comn'iunicating with the aforesaid chambers, said passages` diminishing in area toward the front, and a plurality of spaced openings through which the flames pass to the interior of the kiln, substantially as shown.

6. A tunnel kiln for the purpose set forth, having side ledges and truckways below the plane of said ledges, pipes maintained above the ledges and adjacent to the inner side walls of the tunnel, said pipes terminating within a chamber, a plurality of connected chambers, the rear chambershaving air inlet pipes, chambers into which fuel gas is admitted under a damper control, said chambers communicating with the chambers which receive cold air, chambers having openings, means for supplying heatedair to the last mentioned chambers, and com- In testimony whereof I have heretunto bustiondChan-bers which mlmmunicate with set my hand in the presence of two Witnesses. longitu ina passages aving openings n which communicate With the interior of the JOHN HENRY MARLOW 5 tunnel and are located adjacent to the side Witnesses:

Walls thereof and in proximity to the hot JOHN H. COPESTAKE, air supply pipes. PATTIE PLANT. 

